Bad news for anyone worried about the war widening: Ukraine hit deep inside Russia and Moscow is now talking openly about using nuclear weapons.

• Ukrainian drones struck St. Petersburg during Russia's big investment forum, with reports of civilian deaths and injuries.
• Russia warned it could respond with nuclear weapons, even against nuclear-armed countries it sees as backing the attacks.
• Both sides are stuck in an escalation trap with no real off-ramp, and neither Putin nor Zelensky will name where the war should stop.
• Ukraine can now build its own cheap, precise long-range drones, partly with private Western donor money, so cutting government funding alone won't stop the strikes.
• A push to settle by freezing the war along the current front line, like the Korean War armistice, is the suggested way out.

Outlook: With strikes hitting Russian soil and nuclear threats back on the table, the risk of further escalation is rising unless leaders agree to freeze the front line.